CROWN AS-PISTON 1554336 - Caterpillar

Probable Causes
Inlet manifold pressure sensor
Cold cylinder
Electrical connectors or power supply
Ignition system
Incorrect base timing
Fuel supply
Incorrect air/fuel ratio
Incorrect governor adjustment
Compressor bypass valve
Air inlet restriction
Exhaust restriction
Binding of the throttle actuator
Incorrect valve lash
Cylinder head and related componentsRecommended Repairs
Note: If the symptom only occurs under certain operating conditions such as high idle, full load, and temperature, test the engine under the conditions. Troubleshooting the symptom under other conditions can give misleading results.The Caterpillar Electronic Technician (ET) and the Integrated Temperature Sensing Module (ITSM) can be used to detect a misfiring cylinder. Use the following procedure:
Use the "Data Link/Select ECM" option on the Cat ET to select the ITSM.
Select "Diagnostics/Diagnostic Tests".
Select the suspect cylinder and click the "Start" button in the lower left corner of the screen.Cat ET will display a graph of the cylinder exhaust gas temperature. The output voltage of the transformer secondary circuit, the engine speed, and the desired engine speed are also displayed.Inlet Manifold Pressure Sensor
Engine instability can occur if the inlet manifold pressure sensor reading is incorrect. Stop the engine and check the reading from the sensor. If the pressure is not equal to atmospheric pressure, replace the sensor.Cold Cylinder
Locate the misfiring cylinder. Check the following components for failure: spark plug, extender, ignition transformer and primary wiring. Inspect the extender for signs of pin holes and/or of arcing.Refer to Troubleshooting, "Ignition Secondary - Test".Electrical Connectors or Power Supply
There may be an intermittent interruption of power. Check the wiring harnesses and the connectors. Inspect the connectors in the terminal boxes. Inspect the power supply connections and the ground.Inspect the wiring from the power supply to the control modules. Refer to Troubleshooting, "Electrical Power Supply - Test".Ignition System
Significant improvements have been made to the parts in the ignition system in order to reduce losses in the ignition system. Ensure that current parts are used for the following components:
transformers
extenders
spark plugsInspect the ignition system for the following conditions:
Check the connection between the ignition transformer and the extender. A loose connection can cause arcing and misfires.
Check the connection between the extender and the spark plug for a loose connection or for pin holes that are caused by arcing. Both conditions can cause misfires.
Check the extender for corrosion on the spring. Corrosion may cause arcing through the extender.
Check for corrosion on the terminal of the spark plug and check for wear on the electrode. Both conditions can cause misfires.Other losses or misfire can be caused by shorts or excessive moisture.Maintain the spark plug according to the engine Operation and Maintenance Manual.Check the Base Timing
Verify that the base timing is correct. Refer to Systems Operation/Testing and Adjusting, "Ignition Timing - Adjust".Fuel Supply
Make sure that fuel is supplied at a sufficient pressure that is stable. Make sure that the size of the fuel line is sufficient. Inspect the fuel system for leaks.The following conditions can cause the engine to malfunction:
Low fuel pressure
High fuel pressure
Poor fuel qualityMake sure that the fuel pressure is correct. When possible, interview the operator in order to determine if fuel quality is in